visual
Ai is a petite young Japanese woman, standing at 4'11/''151cm. She has a slim, toned build potentially recognizable as that of a dancer - closest to that of a ballerina (slender, small bust, narrow hips, little visible muscle definition).
Ai is noted in canon to be a particularly bewitching beauty. While she's noted many times to have a pretty face in general, her eyes are what make her truly beautiful. They're a purple fading to pink gradient and are stylized with a six-point star as an expression of how striking and bewitching they're said to be and her eyelashes are thick and full. When she's smiling or laughing – which is often – it's possible to spot that her canines are a little larger than is typical, which gives her smile a slightly playful, catlike air. She has long, deep purple hair with a few stray strands of pink and swept bangs with two chest-length locks framing her face.
Fashion wise, when Ai is out and about in public she tends towards dressing up and looking her best. She always wears 'natural' makeup, enhancing her looks rather than trying to cover them up and tends towards frilly, feminine outfits with a focus on looking pretty, youthful and cute as opposed to striking or mature. To this end, she gravitates towards trendy and fashionable styles like
girly kei and
jirai kei.
When she's dressing for her own comfort or is going incognito, Ai tends towards loose fitting, comfortable clothes -- hoodies, loose t-shirts, oversized jackets and cardigans, etc. When she's in her full cozies, she usually ties up her hair in either braids or a bun.
aural
Ai's voice is high, lively and a little airy - rather than high pitched or squeaky, she sounds clear and sweet. Her natural tone is more soft when she's at ease, but she generally injects a lot of pep and energy when she's talking. In general, she tends to sound a little airheaded or ditzy on a moment to moment basis, emphasized by her floaty, often noncommittal vocabulary. In general, she perfectly embodies what one would expect from a teen idol – at least with her public face. When in private or letting her guard down, her voice becomes a little lower and softer and loses a little of her ditzy edge.
Of note is that Ai is also a professional idol who performs as the lead singer of her best-selling group and she's an exceptionally talented singer as a result. Her Japanese seiyuu is Rie Takahashi and a sample of her voice can be found
here with an example of her singing
here.
Ai speaks Japanese natively and exclusively, with no fluency in any other languages.
demenor
The first and most important thing to note about Ai's presence is that she is absolutely rizzed to the max - she posesses an almost otherworldly level of charisma which is part of what makes her such an incredible idol and when seeing her perform at max power, most people who see her are caught off guard by how captivating they find her. The six-point star her eyes are stylized with is a representation of her beguiling, spellbinding presence and Ai knows very well how to lean into it to do what she needs to do.
This same charisma tends to bleed through into her more normal social interations, though to a much more toned down degree. On a moment to moment basis, Ai generally comes off as a bright, social and well adjusted young woman. The most immediate first impression most people will form of her is of someone who's playful, friendly and airheaded. She's agreeable and gregarious and will rarely speak up in disagreement or anger - in the long term, it will become apparent that she's maybe a bit overly friendly and eager to please, creating the impression of someone who's a bit of a pushover or a people pleaser.
Something very important to note about Ai is that she will often instinctively lie, usually lies of omission and covering up her feelings. She does this effortlessly enough that characters who are actively aware that she lies and are trying to work out what she says it true and isn't can't catch her out on it.
Because of her history of abuse and neglect, Ai lives with the deep seated belief that her true, authentic self is not just unworthy of love but entirely unlovable full stop and that to connect with other people, she must incessently perform as the Ai of B-Komachi - a self described idealized self, a "kind, invincible girl who loves everyone". It's important to note that this idealized self is not an entirely fake mask or a fabrication, but a version of Ai's true self with all her inconvenient humanity airbrushed away. As Ai herself describes it, her public face lacks the real Ai's "dirtiness" and "rough edges".
Observant characters will generally not be able to see through her without long term work and trust, but something that will become apparent are a few things: Ai has difficulty matching names to faces and retaining people's names in general in a way that speaks to faceblindness and neurodivergency as opposed to a lack of care or effort. She lacks common sense in a lot of basic life areas and if confronted on these issues tends to play up a sort of klutzy, charming, childish helplessness.
Finally, Ai also reacts to being yelled at, subjected to someone's anger, physically intimidated or otherwise threatened with physical harm in a way characteristic to someone who has experienced emotional and physical abuse. She tends to freeze up and immediately go as hard on people pleasing and generally framing herself as nonthreatening and dismissable in order to protect herself.
other notes
A flurry of notable things about Ai's general physical presence gets dropped on us in the manga so here's a rapid-fire list of them: Ai has good eyesight along with a sensitive sense of smell and hearing. She takes bigger than average steps when walking and holds her chopsticks 'a little crooked' when eating.
Ai is noted a handful of times to have only completed compulsory education, meaning she left schooling after graduating middle school at 14. Because of this, she is lacking in knowledge of anything that would be taught in the Japanese high school curriculum and has struggles with literacy, being implied in the anime and various side stories to have difficulty with kanji comprehension, though she reads well enough to muddle through and on a day-to-day basis primarily only struggles with names.
Ai can't cook and has anxieties relating to food security, so she relies primarily on premade meals and will do her best to take leftovers and uneaten food from any social gatherings. Because of an instance of physical abuse in her past, she has a specific phobia of white rice and while she can eat it, she will be noticable slow and will take her time.
Ai is canonically noted in the manga to have a developmental disorder, using a term in Japanese that refers to neurodivergencies such as autism, ADHD, Tourettes, etc. While it's never specifically namedropped, I'm like 99.999% certain she is canonically intended to be read as autistic and play her as such.